Have you ever pondered the differences between a house foundation and skirting? And why houses have foundations and why mobile homes get skirting? Ponder no more because I will try to explain the differences here for you. Unlike a stick built home which relies on a perimeter concrete wall placed on footings to support and hold down the perimeter of the home, mobile home skirting isn’t required by mobile home manufacturers to support or hold down the mobile home.
A stick built home or site-built home does not have a steel frame under the wood floor joist system. And because of this it requires wood beams, posts and footings along with a concrete foundation wall. A manufactured home has a steel frame, lag bolted to the joists, which spans the full length of the home and usually supports the floor joist within two feet of the sides of each section.
It’s due to the steel frame that allows the engineers of manufactured homes to design blocking and tie down systems that support from the steel beams to the ground. In addition, there are many options of footings. Such options are as simple as a pressure treated wood block or plastic pier pad. Or at the upper end of the cost bracket you can pour concrete runners or a slab. To help overcome the cost of concrete slabs and runners a manufactured home can be installed with proprietary foundations and tie down systems that are engineered to accomplish the same result with less cost to the user.
The house foundation wall and footing accomplish many things such as:
- a perimeter wall support
- a wind tie down
- a rodent barrier
- rot resistance
- ventilation
- it establishes the depth of the crawlspace.
Aside from the practical uses, foundations also can serve as a backing to a brick of rock veneer or even have a pattern of its own stamped in the concrete.
Manufactured home skirting is not required by the manufacturer to support the perimeter of the 
home, but it is required. The manufacturer requires that skirting be put on to the minimum HUD specifications. Among those specifications are that it must extend from the home to the ground around the perimeter and have the proper ventilation installed in it to the local building code. It also must have an access port to allow a person to crawl under the home for repair work.
HUD has two building standards for skirting. The less restrictive code allows skirting options like the ones that were just mentioned. The more restrictive code is called “The Permanent Foundation Code”, which is found in the “Permanent Foundation Guide for Manufactured Housing”, and requires that the skirting be made of a concrete material. But it still does not require that it must support the home.
Some skirting manufacturers have made skirting that can support the perimeter and these require the approval of a certified engineer. The manufactured home builders allow for proprietary support methods. Engineered skirting can not only support the perimeter of the home but also, in some cases, it can become the perimeter tie down. In the effort to sell their products they have gone as far as to offer different choices of the outward appearance. Although they offer so much they most often don’t get used due to slowing of the building process. Most skirting is installed after the home is blocked, tied down and inspected. When the skirting becomes a component of the support and tie down method it most often requires a special inspection which causes the progress of the job to slow one or two more days while they wait for inspections. This also requires that the installation crew make an additional trip to the site to close up sections of skirting or trim that was left open for the inspector.
The most common forms of skirting that meet the minimum HUD code are vinyl, pressure treated plywood and Duraskirt. These can be installed after the home is blocked and tied down in place. They are used mostly to the fact that they are more affordable. Under the Permanent Foundation Code the most common skirting are CMU block, poured foundation wall and Duraskirt. CMU block and Duraskirt can be installed after the home is set, but a poured foundation usually requires that the home be rolled over the walls and then set down onto the walls. This becomes very costly and adds a certain amount of danger to the job. CMU block requires that it be placed on a concrete footing whether it supports the home or not which makes the cost go up. To overcome this, the builder will extend the slab out beyond the perimeter of the home so the CMU block can be set on the slab. But what if concrete isn’t readily available or is cost prohibitive? This is why so many manufactured home dealerships and contractors use Duraskirt. It doesn’t require a concrete footing under it and it can be installed after the home is set up.
Poured foundation walls are usually just left with the concrete finish that is common to poured walls. There’s nothing wrong with this look as most Americans living in a stick built home have a poured foundation that they don’t have to do anything to maintain. CMU block offers some different choices from smooth to split face and in many colors to choose from. But it still doesn’t give the manufactured home the same appearance as a foundation wall that Americans have come to love. It gives the look of schools, government buildings or shopping centers. Duraskirt offers a residential look that is the closest look to that of a poured in place foundation with its Traditional Smooth finish. It is also offered in the Northwest Exposed Aggregate finish for those that want to match exposed aggregate walkways and driveways.
CMU block cannot legally be used as a perimeter support unless it is installed with filled cavities and has the proper reinforcement added, such as rebar. Most of the time it is installed with the minimum amount of mortar to support the blocks. This creates a “Buyer Beware” situation. When it’s all finished it doesn’t look any different whether the cavities are filled or not. So there is no way for the owner to know whether it was made to support the perimeter or not. Many contractors have been caught trying to get away with the minimum mortar yet still use it as a perimeter support. Make sure when selecting a contractor you get what you’re paying for.
Since manufactured home skirting is not the same as a house foundation and there are so many options to choose from I suggest you search the internet for mobile home skirting ideas. When buying a manufactured home you will want to make a wise choice when it comes to mobile home skirting. The photo below shows Duraskirt concrete panels freshly installed before back-filling. Notice the nice clean residential look for your manufactured home.
